Stems with purplish brown bark; lenticels numerous. Leaves 8--16 cm; petiole 5--8.5 cm; leaflets 3(--5), ovate to ovate-oblong, 3--6 × 2--3.5 cm, leathery, base truncate to cuneate, margin subentire, apex obtuse; primary veins 3 from base. Racemes axillary, 6--8 cm, with 7 or 8 male and 2 female flowers. Male flowers: pedicel ca. 5 mm. Sepals 3 or 4, oblong, 0.9--1.2 cm. Stamens 2.5--3.5 mm. Female flowers: pedicel 1.5--3 cm. Sepals purplish black, sublinear to narrowly oblong, 2.2--2.7 cm. Carpels 4--6, cylindric, 4--6 mm. Fruit not seen. Fl. Apr.

* Semideciduous forest margins, hillsides, by streams; 600--800 m. SE Gansu (Wen Xian).